Prior art document WO2015075222 discloses a scanning MEMS reflector applicable in LIDAR applications and actuated by piezoelectric elements. In the disclosed solution, piezoelectric actuators are fixed to the edge of a reflector with springs. The vertical displacement created by the piezoelectric actuators is transferred directly to the edge of the reflector. As seen in FIG. 4 in document WO2015075222, a problem with this prior art solution is that the actuation units (3) require a very large surface area to be able to generate a sufficient actuation range. The reflector 1 occupies only a small area in the middle of the device. The large chip size required of the scanning MEMS reflector disclosed in WO2015075222 limits its versatility.
US2006227409 and US2007171500 are two prior art documents where mechanical amplification has been utilized to increase the tilt amplitude of MEMS reflectors. However, both of these prior-art solutions for mechanical amplification require a great deal of surface area. They cannot be used with large-area reflectors and they require a large chip size even for small-area reflectors. Furthermore, neither of them can generate wobbling-mode oscillation.